The Simplon Sengo Urban 80 is light, it has a super-powerful motor and it's masses of fun to ride. If you've got four grand to drop on a bike for larking about on you can do a whole lot worse than this. It's not altogether the most practical of beasts, and if you're after full utility or proper off-road capability then your money is probably better spent elsewhere, but if you want an exciting all-purpose fast commuter or leisure bike then there's not much I've ridden that fits the bill better than this.

Is the Sengo an urban bike? Well, nominally it is: those Schwalbe Super Moto tyres are designed for the asphalt, and it's got a plumbed-in front light and comes with a Busch & Müller battery rear too. Oh, and it has a kickstand. It's a very stripped back urban bike though: there are no mudguards, nor any means of fitting them, and the look is very much cafe-racer-meets-mountain-bike rather than your average shopper. The frame is Simplon's Sengo 27.5 carbon mountain bike frame; they do proper off-road builds of this bike too, with knobbly tyres and suspension forks. But if you're after a fast, stripped-back cruiser then they don't come much faster or more stripped back than this.

The Sengo gets the full-fat Bosch Performance Line CX motor and a chunky 500Wh battery, but in spite of that tips the scales at only just over 18kg: that's the lightest Bosch-powered bike we've had through the door, without really trying too hard. The finishing kit is good quality stuff but mostly falls into the durable camp, rather than the lightweight one.

Gears are supplied by Shimano, from their XT mountain bike groupset. That's one below the top tier so it's quality stuff, and the 11-42 cassette will give you a range of gears for pretty much anything you're likely to throw this bike at.

The Sengo's frame has slightly dropped and bent seat stays, and they're flattened in order to allow a bit of flex and keep the back end more comfortable. The compact nature of the frame and the small-bore carbon seatpost will also help there. Up front you get a full carbon fork that's nice and tall to keep the bike's geometry correct when it's not running suspension. There's plenty of room inside for the massive 70mm Super Moto tyres, which are running on 25mm rims.

Jez says: It's a curious beast, this; a fully-rigid hardtail with big fat tyres, ultra-light for a e-bike on account of the full carbon construction, yet set up to handle almost like a big downhill rig, lack of suspension notwithstanding. The Simplon likes to be guided rather than hustled; steering is leisurely rather than XC-sharp.

As we found with the Fantic Sport fat bike, big tyres are not a substitute for suspension when it comes to either off-road handling or comfort, so despite the burly looks, the Simplon is best viewed as a sort of fast, urban messing-about sort of bike rather than a bona fide e-mtb.

Those tyres do provide good traction in a range of conditions, though, and despite not being set up as tubeless, I liked them best with fairly low pressures, to prioritise comfort over low rolling resistance, which is never as important on an e-bike.

Bosch's class-leading drive system is a familiar and welcome choice by now, providing smooth and powerful assistance.  The wide 11-speed cassette gives a big spread of gears, the lowest of which will get you up pretty much anything. 

Shimano hydraulic discs with big 160mm rotors provide seriously powerful stopping - one-finger braking is enough to stand the bike on its nose - but with really excellent modulation and control.  Finally, the practicality boxes are ticked - there are bosses to mount a rear pannier rack, and a kickstand is fitted too. It's odd that Simplon have integrated a front light but the back light has to be operated and charged independently.

Dave says: You can't see my face while I'm writing this but imagine it with a big grin: the Simplon Sengo 27.5 Urban 80 is proper fun. So far, this is the bike that's garnered the most interest in the office, and when out and about. Literally everyone wants a go on it, and so far no-one has been disappointed. The Sengo really is a great bike to ride.

Having an 18kg all-in weight and Bosch's top-line motor helps, of course. This Simplon is about 4kg lighter than most urban bikes, and with 75Nm of torque on offer from the mid motor the acceleration response from the lights is incredible. It's a handful of pedal strokes before you've topped out at 25km/h and you're on your own. You have to rein yourself in a bit to keep the motor assistance going, especially in the higher modes. In Eco and Tour modes it's very easy to cruise along, with the buzz of the huge tyres drowning out the motor.

Ah, those tyres. Schwalbe's 70mm Super Moto rubber is very sticky, and the round profile means that the lean limit of this bike round the corners is somwhere a lot lower than my instincts for self-preservation will let me go. They also allow you to run very low pressures – I've had as low as 20psi in them – which instantly makes the bike a lot more comfortable, especially on rougher off-road surfaces.

That tyre comfort is most in need at the front, where the super-rigid fork does a great job of letting you know what's going on in terms of lumps and bumps. It's certainly direct and the steering is very precise even though it's pretty relaxed, but it can beat you up a bit if there's too much air in the tyres. At the back the Sengo is more comfortable; the flattened seat stays help a bit but mostly it's down to the low frame design, which means you run a lot of exposed seatpost, and there's plenty of flex in the carbon 'post that the bike comes with. I hated the saddle but if you're dropping four grand on a bike you can probably stretch to one you like.

I've mostly run the Sengo as an urban runabout and it's a very capable and responsive bike for commuting and nipping around town. Once you take it off-road you're fine on graded surfaces but as things get more technical you start to notice the lack of traction from the tyres and lack of suspension holding the bike back a bit. If you swapped the street tyres for some chunkier off-road rubber you could easily do some trail riding on the Sengo, but if that's a priority there are many better ways to spend your money.

In spite of the stripped back look the Sengo is fairly practical: There's a kickstand, you can fit a rack if you want, and you get lights too. The Busch & Müller front light is plmubed in and it's pretty decent. The rear light is about as basic as they come: it has one mode (two if you count 'off') and it's not very bright. It's separate to the motor system, too.

Shimano's XT drivetrain gave us no surprises: the shifting is quick and accurate and there's a wide spread of gears available. There was nothing on- or off-road that the Simplon didn't manage with ease, and assuming that you're mostly riding around within the assistance limit you won't run out of gears at the other end either. 

Overall the Sengo does a great job of being fun and reasonably practical. Sure, it's a lot of money to throw at a bike that's maybe not as practical as some of the other options out there, but the lightweight, stripped-back aesthetic will appeal to some riders and there's no doubt the ride will too. If you're after a genuine all-weather, all-year workhorse then this probably isn't it. If you want a fun bike for leisure riding, with a bit of practicality built in, it might well be. Assmunig your pockets are deep enough...